“It’s not unusual for something like this to roll through without much fanfare,” she said of the bill that passed.

McCaskill told CBS News that it’s realistic her bill could pass.

Sen. Claire McCaskill

“I think that it’s realistic. I do sense that there is a bipartisan kind of ‘we’ve got a crisis’ attitude about opioids now,” she said.

One of the bill’s authors, Rep. Marsha Blackburn, R-Tennessee, said via a spokesperson Monday that “if there are any unintended consequences from this bipartisan legislation … they should be addressed immediately.”

Many lawmakers are still trying to figure out why DEA and the DOJ dropped their initial opposition to the bill. That would have ensured more scrutiny before a vote, and it’s a sign that even some in law enforcement may not have realized how much this law would tie the DEA’s hands.